Add RHEL-8.4 image test case manifests for all architectures. The set of
image types per architecture is based on what is currently available for
RHEL-8.3.
The image test case for RHEL-8.4 tar image on s390x is not added yet
because of Issue #1220.
Fixes#1167
Signed-off-by: Tomas Hozza <thozza@redhat.com>